Ultra-low cost high performance satellite aperture

ABSTRACT

An antenna system of a satellite may consist of an antenna receiver that is coupled to a plurality of flexible couplings. The couplings may each be affixed to one or more antenna elements. The couplings may be deployed in space in an uncontrolled manner. Additionally, the spacing between the couplings, and in turn the antenna elements, may be spaced in an uncontrolled manner. The antenna elements may have no pointing requirements. The antenna system may receive training signals and associate an antenna element to a time of arrival based on the training signal. Upon receiving a data signal, the antenna system may apply coefficients determined from the association of the antenna element to the time of arrival to the data signal to discover wanted signal coherence among the antenna elements.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present Application for Patent is a 371 national phase filing ofInternational Patent Application No. PCT/US2020/017847 by ROBINSON, etal., entitled “ULTRA-LOW COST HIGH PERFORMANCE SATELLITE APERTURE,”filed Feb. 12, 2020, which claims the benefit of U.S. Provisional PatentApplication No. 62/804,476 by PARKER et al., entitled “ULTRA-LOW COSTHIGH PERFORMANCE SATELLITE APERTURE,” filed Feb. 12, 2019, and claimsthe benefit of U.S. Provisional Patent Application No. 62/808,554, byPARKER et al., entitled “ULTRA-LOW COST HIGH PERFORMANCE SATELLITEAPERTURE,” filed Feb. 21, 2019, each of which is assigned to theassignee hereof, and each of which is expressly incorporated byreference in its entirety herein.

BACKGROUND

The following relates generally to antenna systems, and morespecifically to an ultra-low cost high performance satellite aperture.

In satellite systems, many different antenna types are used withspecialized properties for particular applications. For example, asatellite may utilize a dish antenna to receive and transmit signals.The dish antenna may consist of a parabolic reflective surface and acentral feed horn. The parabolic surface facilitates the convergence ofincident beams where the incident beams are reflected to the centralfeed horn, which is positioned at the focal point of the curvature. Whenthe dish antenna receives signals, the incoming signal becomes much moreconsolidated due to the combined energy of individual radio signals.Another example of an antenna is an active electronically scanned array(AESA). An AESA is a type of phased array antenna in which the beam ofsignals can be steered electronically in any direction, withoutphysically moving the antenna. The antenna consists of an array ofregularly spaced small antennas each with a separate feed. The beam issteered electronically by controlling the phase of the radio wavestransmitted and received by each of the multiple radiating elements inthe antenna. This digitally controlled scanning nature of the AESAallows it to quickly scan any direction in comparison to a mechanicallyscanned radar, whose range is constrained by the direction it is facingand how quickly its motors can turn it.

However, each antenna type has certain drawbacks that make themill-suited for every application. For example, each antenna type variesin size, mechanical complexity, power, cooling, weight, price, etc.,which may dictate which antenna is to be used for a particular function.In some cases, an antenna that is uncomplicated mechanically and lowcost may be desired.

SUMMARY

The described techniques relate to improved methods, systems, devices,and apparatuses for an ultra-low cost high performance satelliteaperture. An antenna system of a satellite may consist of an antennareceiver that is coupled to a plurality of flexible couplings. Thecouplings may each be affixed to one or more antenna elements. Thecouplings may be deployed in space in an uncontrolled manner.Additionally, the spacing between the couplings, and in turn the antennaelements, may be spaced in an uncontrolled manner. The antenna elementsmay have no pointing requirements. The antenna system may receivetraining signals and associate an antenna element to a time of arrivalbased on the training signal. Upon receiving a data signal, the antennasystem may apply coefficients determined from the association of theantenna element to the time of arrival to the data signal to discoverwanted signal coherence among the antenna elements.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 illustrates an example of a system for wireless communicationsthat supports an ultra-low cost high performance satellite aperture inaccordance with aspects of the present disclosure.

FIG. 2 illustrates an example of a satellite for wireless communicationsthat supports an ultra-low cost high performance satellite aperture inaccordance with aspects of the present disclosure.

FIG. 3A and FIG. 3B illustrates an example of a satellite for wirelesscommunications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.

FIG. 4 illustrates an example of a satellite antenna for wirelesscommunications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.

FIG. 5 shows a block diagram 500 of an apparatus 505 for an ultra-lowcost high performance satellite aperture in accordance with aspects ofthe present disclosure.

FIG. 6 shows a flowchart illustrating a method 600 that supports anultra-low cost high performance satellite aperture in accordance withaspects of the present disclosure.

DETAILED DESCRIPTION

The described features generally relate to an antenna system where theantenna elements of the system each have an imprecise placement inspace. Each of the antenna elements may be flexibly coupled to anantenna receiver, and the couplings may be deployed in space in anuncontrolled manner. Upon receiving data signals from a transmitter, theantenna system may apply linear algebra and multiple-inputmultiple-output (MIMO) signal processing to discover signal energycoherence to coherently add all the collected signal energy.

In contrast to other antenna systems, such as dish antenna systems, thepresent antenna system has low mechanical complexity and may be producedat low relative cost. For example, a dish antenna may have highmanufacturing tolerances to maintain signal energy coherence. Also thehigh gain of the present system would be equivalent to the gain of adish antenna with a very large diameter. Using a dish antenna with avery large diameter would not only increase manufacturing cost, but alsoits use would increase other costs such as transportation andintegration costs since the dish antenna would need to be transportedand assembled in space. In addition, the directionality of the presentantenna system is configurable as opposed to conventional antennasystems, reducing mechanical complexity involved in antenna pointing.

This description provides examples, and is not intended to limit thescope, applicability or configuration of embodiments of the principlesdescribed herein. Rather, the ensuing description will provide thoseskilled in the art with an enabling description for implementingembodiments of the principles described herein. Various changes may bemade in the function and arrangement of elements.

Thus, various embodiments may omit, substitute, or add variousprocedures or components as appropriate. For instance, it should beappreciated that the methods may be performed in an order different thanthat described, and that various steps may be added, omitted orcombined. Also, aspects and elements described with respect to certainembodiments may be combined in various other embodiments. It should alsobe appreciated that the following systems, methods, and devices mayindividually or collectively be components of a larger system, whereinother procedures may take precedence over or otherwise modify theirapplication.

FIG. 1 is a simplified diagram of a satellite communications system 100in which the principles included herein may be described. The satellitecommunications system 100 may provide a communication service across atleast portions of a visible earth area from the position of thesatellite 105. Satellite 105 may be any suitable type of satellite, forexample a geostationary orbit (GEO) satellite, medium earth orbit (MEO)satellite, or low earth orbit (LEO) satellite. Satellite may provide thecommunication service via user beams 145, which may each providecoverage for a user beam coverage area. Although only a single user beam145 is illustrated, satellite 105 may be a multi-beam satellite,transmitting a number (e.g., typically 20-500, etc.) of user beams 145each directed at a different region of the earth. This can allowcoverage of a relatively large geographical area and frequency re-usewithin the covered area. Frequency re-use in multi-beam satellitesystems permits an increase in capacity of the system for a given systembandwidth.

Each satellite beam 145 of the satellite 105 may support a number ofuser terminals 185. User terminals 185 may receive data from satellite105 via forward downlink signals 155-a and transmit data via returnuplink signals 160-a. A user terminal 185 may be any two-way satellitefixed or mobile ground station such as a very small aperture terminal(VSAT). Each satellite beam 145 may support other terminals such asmulti-user access terminals 170, which may also be fixed or located on amobile platform 130 such as an aircraft, ship, vehicle, train, or thelike. As illustrated in FIG. 1, a satellite beam 145, which may beassigned to a particular frequency range and polarization, may carryforward downlink signals 155 or return uplink signals 160 for both fixedterminals 185 and multi-user access terminals 170. The forward downlinksignals 155 or return uplink signals 160 for user terminals 185 andmulti-user access terminals 170 may be multiplexed within the satellitebeam 145 using multiplexing techniques such as time-division multipleaccess (TDMA), frequency-division multiple access (FDMA),multi-frequency time-division multiple access (MF-TDMA), code-divisionmultiple access (CDMA), orthogonal frequency division multiple access(OFDMA), and the like.

Satellite communications system 100 includes a gateway system 115 and anetwork 120, which may be connected together via one or more wired orwireless links. Gateway system 115 is configured to communicate with oneor more user terminals 185 or multi-user access terminals 170 viasatellite 105. Network 120 may include any suitable public or privatenetworks and may be connected to other communications networks (notshown) such as the Internet, telephony networks (e.g., Public SwitchedTelephone Network (PSTN), etc.), and the like. Network 120 may connectgateway system 115 with other gateway systems, which may also be incommunication with satellite 105 or other satellites. Alternatively, aseparate network linking gateways and other nodes may be employed tocooperatively service user traffic. Gateway system 115 may also beconfigured to receive return signals from user terminals 185 ormulti-user access terminals 170 (via the satellite 105) that aredirected to a destination in network 120 or the other communicationnetworks.

Gateway system 115 may be a device or system that provides an interfacebetween network 120 and satellite 105. Gateway system 115 may use anantenna 110 to transmit signals to and receive signals from satellite105 via a forward uplink signals 135 and return downlink signals 140.Antenna 110 may be two-way capable and designed with adequate transmitpower and receive sensitivity to communicate reliably with satellite105. In one embodiment, satellite 105 is configured to receive signalsfrom antenna 110 within a specified frequency band and specificpolarization. Although illustrated as including one satellite 105,satellite communications system 100 may include multiple satellites. Themultiple satellites may have service coverage areas that at leastpartially overlap with each other.

Each satellite user beam 145 of satellite 105 supports user terminals185 or multi-user access terminals 170 within its coverage area (e.g.,providing uplink and downlink resources). Frequency re-use betweensatellite user beams 145 may be provided by assigning one, or more,ranges of frequencies (which may be referred to as channels) to eachsatellite user beam 145 and/or by use of orthogonal polarizations. Aparticular frequency range and/or polarization may be called a “color,”and frequency re-use in a tiled spot beam satellite system may beaccording to color.

The coverage of different satellite user beams 145 may benon-overlapping or have varying measures of overlap, up to and includinga 100% overlap. In one example, satellite user beams 145 of satellite105 may be tiled and partially overlapping to provide complete or almostcomplete coverage for a relatively large geographical area wherepartially overlapping or adjacent beams use different ranges offrequencies and/or polarizations (e.g., different colors).

Satellite 105 may provide network access service to communicationdevices (e.g., computers, laptops, tablets, handsets, smart appliances)connected to user terminal 185 or to communication devices 175 ofpassengers 180 on board mobile platform 130. For example, passengers 180may connect their communication devices 175 via wired (e.g., Ethernet)or wireless (e.g., WLAN) connections 176. Multi-user access terminal 170may obtain the network access service via user beam 145.

Multi-user access terminal 170 may use an antenna 165 mounted on mobileplatform 130 to communicate via forward downlink signals 155-a andreturn uplink signals 160-a. Where multi-user access terminal 170 islocated on a mobile vehicle, antenna 165 may be mounted to an elevationand azimuth gimbal which points antenna 165 (e.g., actively tracking) atsatellite 105. Satellite communications system 100 may operate in theInternational Telecommunications Union (ITU) Ku, K, or Ka-bands (forexample from 17.7 to 21.2 Giga-Hertz (GHz) in the downlink and 27.5 to31 GHz in the uplink portion of the Ka-band). Alternatively, satellitecommunications system 100 may operate in other frequency bands such asC-band, X-band, S-band, L-band, UHF, VHF, and the like.

It should be appreciated by a person skilled in the art that one or moreaspects of the disclosure may be implemented in a system 100 toadditionally or alternatively solve other problems than those describedherein. Furthermore, aspects of the disclosure may provide technicalimprovements to “conventional” systems or processes as described herein.However, the description and appended drawings only include exampletechnical improvements resulting from implementing aspects of thedisclosure, and accordingly do not represent all of the technicalimprovements provided within the scope of the claims.

In one example, satellite 105 includes or is coupled with an antennasystem 101 which includes an antenna transceiver system that is coupledto a plurality of flexible couplings. The couplings may each connect thereceiver to one or more antenna elements. The antenna transceiver systemmay have one or more transceivers. The antenna system may be 101 may bepackaged for deployment of satellite 105 in a compact arrangement of theflexible couplings and the antenna elements. Once the satellite 105reaches a target orbit (e.g., LEO, MEO, GEO), the couplings may bedeployed in space to spread the antenna elements over an area for theaperture of the antenna system. The deployed locations of each antennaelement may not be predetermined or controlled during deployment. Thus,the spacing between the couplings, and in turn the antenna elements, maynot be predefined prior to deployment, and may be spaced in anuncontrolled manner by the physical properties of the flexiblecouplings. Satellite 105 may possess one or more features as describedherein with respect to the disclosed antenna system 101.

After deployment, antenna system 101 of satellite 105 may receivetraining signals from various transmitting devices, such as antenna 110,user terminal 185, or antenna 165. One or more antenna elements ofantenna system 101 may receive these training signals and a processor ofantenna system 101 may determine position-related information such astime-of-arrival (TOA) parameters and associate the TOA parameters torespective antenna elements. Antenna system 101 may further determinereception coefficients based on the TOA parameters. Each coefficient maybe based on a unique (e.g., per transceiver) time of arrival signature(e.g., eigenmode). Antenna system 101 may receive subsequent signalsfrom antenna 110, user terminal 185, or antenna 165 such as datasignals, and a processor of antenna system 101 may process the datasignals utilizing the coefficients. The transmitter transmitting thedata signals may be a same or different transmitter from the one thattransmitted the training signals.

Antenna system 101 may also allow frequency re-use between satelliteuser beams 145 to be obtained by the unique weighting of time-of-arrivalbetween satellite user beams 145 end points where user beam end pointsare the satellite 101 and terminals (e.g., antennas of user terminal 185or multi-user access terminal 170). Because the weighting oftime-of-arrivals is unique, the signal communications carried bysatellite user beams 145 may be uniquely separated from other satelliteuser beams (e.g., through linear algebra). For example, each user beam145 may be associated with a different set of coefficients. Hence theentire frequency assigned to each satellite user beam 145 may be reusedby other satellite user beams with no or negligible impairment of systemcommunication performance. The uniqueness of weighting oftime-of-arrival between satellite user beams 145 and end points may bedetermined by the diameter of a volumetric 3D shape of antenna system101, the number of antenna elements of antenna system 101, theseparation between user terminals, or a combination thereof.

Multiple satellite user beams 145 and signals associated with the beamshaving the same frequency range can be received at the same time anddistinguished via weighting coefficients. The size of the volumetricshape and number of elements determine the spatial or geographicresolution for distinguishing signals from different transmitters usingdifferent angles of arrival. The design may be able to achieve aresolution in the 100 m to 1 km range (e.g., with a volumetric 3D shapeof approximately 1 km and 1,000 elements in a LEO configuration), andthus may support very small effective user beams.

FIG. 2 illustrates an example of an antenna system 101-a for wirelesscommunications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.Antenna system 101-a may include antenna transceiver system 240,branches 210, antenna elements 215, and couplings 220, and may be partof or coupled with a satellite 105. Antenna system 101-a may be anexample or implement aspects of antenna system 101 of FIG. 1. Antennasystem 101-a may be an example of an n-layer MIMO antenna. In someexamples, antenna system 101-a may be a 2-layer MIMO antenna.

Antenna transceiver system 240 may receive signals, such as trainingsignals and data signals. Antenna transceiver system 240 may includemultiple transceivers 235 and a processor 245. Each transceiver 235 maybe connected to one or more antenna elements 215 (or leaf antennas), viaa flexible coupling 220. Flexible coupling 220 may be constructed out ofa flexible or semi-rigid material (e.g., wire, coated wire, coaxialcable, twisted pairs of wires, shielded wires, electrically conductivemechanical swivels, springs, rotators, gimbles, etc.) that electricallycouples to the one or more antenna elements while not constraining thedeployed location of the one or more antenna elements 215 in eachdimension. That is, the deployed positions of the one or more antennaelements 215 may be constrained by their position along the flexiblecoupling, but may otherwise be unconstrained in one or more spatialdimensions. In some cases, the manner of an uncontrolled deployment ofantenna elements 215 is within a range of pliability of flexiblecoupling 220. In some examples, antenna elements 215 may be attached toflexible coupling 220 via a coupler while in other examples, antennaelements 215 may be directly attached to flexible coupling 220. Althoughthe precise positioning of antenna elements 215 may be uncontrolled,spatial separation of the antenna elements may allow for mutual couplingto be insignificant. In some examples, antenna system 101-a may includea quantity of antenna elements 215 greater than 100, or greater than1000.

The energy received by antenna system 101-a may be proportional to thesum of the cross-sectional area of the effective aperture of antennaelements 215. The array gain of antenna system 101-a may be the sum ofsignal energy collected from the effective aperture of each antennaelement 215. The gain of antenna system 101-a may be expressed as:

(gain per antenna element)+10 log (number of antenna elements)

Antenna elements 215 may be randomly oriented (e.g., spatial locationsnot predetermined or precisely controlled) and may feature a largesatellite aperture baseline. For example, antenna elements 215 mayfeature a baseline of greater than 100 meters, greater than 200 meters,greater than 500 meters, greater than a kilometer. Antenna system 101-amay use various types of antenna elements 215 (e.g., dipole, biconic,monopole, patch), and each antenna element 215 may be the same type, orantenna system 101-a may use a combination of different types, in somecases.

In their totality when deployed, antenna elements 215 may form avolumetric shape. In some examples, at least one dimension of thevolumetric shape may be more than 100 times a distance of a wavelengthof a data signal. In another example, an orientation of the volumetricshape is uncontrolled relative to an orbital position of the satellite,and in some cases an orientation of satellite 105 or antenna system101-a may be uncontrolled during orbit (e.g., satellite 105 or antennasystem 101-a may not use active attitude control). In some examples, thevolumetric shape may be roughly spherical such that signals transmittedfrom any arbitrary angle and traversing the volumetric shape include atraversal of a diameter 250 (e.g., at least a minimum diameter) of thevolumetric shape.

Antenna system 101-a may have the same number of transceivers 235 asantenna elements 215. For example, each of antenna elements 215 may belinked to its own transceiver 235 (e.g., each transceiver 235 may becoupled with a single antenna element 215). Alternatively, antennasystem 101-a may have fewer transceivers 235 than antenna elements 215(e.g., each transceiver 235 may be coupled with more than one antennaelement 215).

In some examples, each of antenna elements 215 may be connected to atransceiver 235 via a series of branches 210 and leaves 220, with eachbranch 210 connected to one or more leaves 220, and with each leaf 220connected to one or more antenna elements 215. In some examples, thequantity of branches 210 may be the same as the quantity of transceivers235. For example, at least a subset of the branches 210 may include morethan one antenna element 215, and each transceiver 235 may be coupledwith one branch 210. The number of antenna elements 215 may be identicalacross all branches 210 or they can be different to optimize the antennaarray or for power management, interference tolerance, or failed antennaelements. Each branch 210 may include thermal management (e.g., aheating element), and power or amplification components. Each leaf 220may couple one or more antenna elements 215 to the branch 210 via adirect connection or a coupling (e.g., RF coupler). Each branch 210 mayinclude components for pre-processing RF signals from the leaves 220coupled with the branch 210. For example, each branch 210 may includeanalog or digital processing components such as filters, low-noiseamplifiers, high-power amplifiers, phase shifters, mixers,analog-to-digital converters, or other signal processing components. Insome examples, each branch 210 includes analog weighting circuitry(e.g., phase shifters, amplitude modulators) for applying analogbeamforming weights to signals transmitted or received via the leaves220 of the branch.

Each transceiver 235 may include components for RF communications (e.g.,filters, a low-noise amplifier, high-power amplifiers, mixers,analog-to-digital converters, demodulators, or other signal processingcomponents). For example, each transceiver 235 may include circuitry forMIMO processing such as for maximum ratio combining (MRC) of the signalsfrom each branch 210, leaf 220, or antenna element 215 to which it iscoupled.

Each branch 210 may be considered a sub-aperture of the totalsynthesized aperture of antenna system 101-a. Although not controlled tobe predetermined distances, each branch 210 may be separated fromanother by a branch distance 225 and each leaf 220 or antenna element215 may be separated from another by leaf distance 230. Thus, branchdistance 225 and leaf distance 230 may be illustrated as average orminimum separable distances, while actual branch distances and leafdistances 230 between different branches 210 and leaves 220 may vary.Branch distance 225 or leaf distance 230 may provide sufficientseparation between branches or leaves such that a time of arrivalbetween the branches or leaves may be easily measured. For example,light travels one meter in 3.3 nanoseconds. Assuming that there is a 100ns discrimination between time of arrival to match conventional digitallogic processing, branch distance 225 or leaf distance 230 may beapproximately 30 meters. Assuming that there is a 10 ns discriminationbetween time of arrival to match conventional digital logic processing,branch distance 225 or leaf distance 230 may be approximately 3 meters.Leaf distance 230 may be separated by a sufficient distance to simplifythe radiation pattern into separate and independent collections of thebase antenna element radiation pattern. For example, each branch mayinclude leaves 220 or antenna elements 215 spaced along its length bythe leaf distance 230 to provide discrimination in time of arrival foreach leaf 220 (assuming relatively low fold over or loop back of thebranch 210. In some cases, some antenna elements 215 may end up having aleaf distance 230 of less than the minimum distance for discrimination.Where antenna elements 215 having less than a minimum leaf distance fordiscrimination are coupled with different transceivers 235 (e.g., viadifferent branches 210), the signals may be discriminated via thedifferent transceivers. Where the antenna elements 215 are coupled withthe same transceiver 235, coefficients may be combined or the signal maybe suppressed to reduce the effects of the composite signal for theantenna elements 215 without being discriminated.

In some cases, leaf distances 230 or branch distances 225 may bemaintained using mechanical devices. For example, semi-rigid members(not shown) may be connected at a location along branches 210 and mayprovide a separating force that may tend to keep branches 210 apart fromeach other. The members may be foldable or collapsible for packaging forlaunch and orbit insertion of a satellite 105. In other examples, theleaves 220 or branches 210 may be connected to an inflatable structure(e.g., balloon) that is inflated upon deployment. In other examples, aweighted object coupled with an end of a branch 210 may be ejected(e.g., via a spring) from satellite 105, and may extend a flexiblecoupling (e.g., wire) of the branch to a desired extension fromsatellite 105. In yet other examples, the mechanical force formaintaining branch distances 225 or leaf distances 230 may come fromcentrifugal force in deployment or operation. For example, a satellite105 may be inserted into an orbit with a rotation or may use an attitudeadjustment mechanism to establish a rotation, and the centrifugal forcefrom the rotation may assist in maintaining the leaf distances 230 orbranch distances 225.

In addition to forces from pneumatic (inflation), spring, andcentrifugal forces, additional examples for deploying leaves 220 orbranches 210 and creating separation for leaf distances 230 or branchdistances 225 include: mechanical ratchets or pawls; chemical reactionswhich may change structure and harden after deployment to maintain orguide leaf distances 230 and branch distances 225; electrostatic forceswhich attract or repel leaves 220 and branches 210; or thermal expansionof the mechanical structures which connect the leaves 220 and branches210. In some instances, miniature reaction jets, pyrotechnic devices, orion thrusters may be used to deploy, maintain, or guide leaf distances230 and branch distances 225 (e.g., to maintain a minimum distance,without strictly controlling position). Any combination or individualselection of these methods may be used.

In one example of a combination of these methods, a large array of patchantennas may be assembled as leaves 220 covering all 4 Pi steradians onan inflatable ball which also serves as a ground plane. These patchantenna leaves 220 may connect via flexible connectors to branches 210which individually connect back to the satellite 105 (e.g., totransceivers 235). At deployment, spring forces may be used to eject thebranches 210 outward which may contain uninflated patch antennas. Onreaching deployment, a chemical reaction may be used to harden thebranches 210 and the leaves 220 including inflatable balls of patchantennas (which may be pyrotechnically inflated using pneumatic force tocomplete the deployment).

In a second example of how these methods may be combined, a large arrayof biconic antennas may be assembled as biconic antenna leaves 220 andmay contain a mechanical spring which assumes a proper shape on releasefrom a confining constraint. These biconic antenna leaves 220 mayconnect via flexible connectors to branches 210 which individually mayconnect back to the satellite 105. At deployment, pneumatic forces maybe used to inflate the branches 210 which may extend the branchesoutward and simultaneously release the biconic antenna leaves 220 fromtheir confining constraint allowing the spring force to force each leaf220 into a predefined shape. On reaching deployment, a chemical reactionmay be used to harden the inflated branches to complete the deployment.

In a third example of how these methods may be combined, a large arrayof dipole antennas may be assembled as leaves 220 and may contain amechanical spring which assumes a predefined shape on release from aconfining constraint. These dipole antenna leaves 220 may connect viaflexible connectors to branches 210 which individually may connect backto the satellite 105. At deployment, spring forces may be used to launchthe branches 210 outward which may release the dipole antenna leaves 220from their confining constraint allowing the spring force to force eachleaf 220 into the predefined shape. Electrostatic forces may be appliedto each branch 210 and to each leaf 220 of like charge, forcing eachleaf 220 and branch 210 to repel each other to complete the deployment.

In a fourth example of how these methods may be combined, a large arrayof mixed antenna types of leaves consisting of monopole and patchantennas may be assembled as leaves 220. The leaves 220 may cover all 4Pi steradians on a ball which may use spring tension to maintain itsshape and may also serve as a ground plane. These monopole and patchantenna leaves 220 may connect via flexible connectors to branches 210which individually may connect back to the satellite 105. At deployment,spring forces may be used to launch the branches 210 outward which mayrelease the monopole and patch antenna ball leaves 220 from theirconfining constraint allowing the spring force to force each leaf 220into the proper shape. In conjunction with the initial spring forces forlaunching the branches 210 outward, thermal energy received from the sunmay strike each branch 210 and the material of each branch may expand,forcing a mechanical network of ratchets and pawls to lock into placeand forcing each leaf 220 and branch 210 to complete the deployment.

Interference tolerance within the linear dynamic range of antenna system101-a is managed via the MIMO selection of the data signal. Interferencetolerance (dynamic range compression) is managed via the ratio of thenumber of antenna elements 215 needed to close the link between a userterminal on the ground, satellite 105, and the total number of antennaelements 215.

FIG. 3A illustrates an example of a signal receiving technique 300 forwireless communications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.In some examples, antenna elements 305 may implement aspects of antennaelements 215 as described in FIG. 2.

Transmitting devices such as antenna 110 and/or user terminal 185 maysend training signals 310 to antenna elements 305 prior to sending datasignals 315. Training signals (e.g., 310-a, 310-b, . . . 310-n) mayarrive at antenna elements 305 sequentially or in any overlapping order.In some examples, training signals 310 may be received concurrently(e.g., at least partially overlapping in time) at antenna elements 305(e.g., and over the same frequency) if training signals 310 are comingfrom locations separated by a minimum spatial or geographic resolution(e.g., 100 m 1 km range). Training signals 310 generally comprisesequences that are known in advance to satellite 105. Training signals310 may be encrypted in order to authenticate and ensure that trainingsignals 310 from valid user terminals are processed. In some examples,training signals 310 are orthogonal sequences.

Training signals 310 may also convey additional information (e.g.,through the use of multiple available sequences). In some examples,training signals 310 may include location information for a userterminal. For example, a user terminal could know its location (e.g.,via GPS or other geolocation signals), and in some cases, may indicate acode associated with the location in the training signals 310. In oneexample, each user beam is associated with a different code, and a userterminal may determine which beam is serving the user terminal (e.g.,using the location information and stored beam coverage areainformation, or using received signals indicating the user beam). Theuser terminal may then select a code associated with the beam, or one ofa group of codes associated with the beam (e.g., randomly). In somecases, the information may include a priority for the communications.For example, a certain user may have priority or may select betweenmultiple priorities based on a type of data for communication. In otherexamples, training signals 310 may include information such as userterminal type, user type, etc. In some examples, the same transmittingdevice may send training signals 310 and data signals 315. In otherexamples, the transmitting device sending training signals 310 may bedifferent from the transmitting device sending data signals 315. Due toantenna elements 305 shifting in space or changing attitude (e.g.,without attitude control during orbit), antenna system 101 maycontinually or periodically receive training signals 310 for properchannel tracking as the channel and the distance from a particularantenna element 305 to the transmitting device regularly changes.

A transceiver (e.g., transceiver 235) may receive a training signal310-a from one or more antenna elements 305 (e.g., antenna element305-a, antenna element 305-b, and antenna element 305-n). A trainingprocessor of antenna system 101 (e.g., processor 245) may receive thesignals from each respective antenna element 305 (e.g., from one or moretransceivers) and determine a time of arrival for each of antennaelements 305 based on the received training signal 310-a. A beam weightprocessor of antenna system 101 (e.g., processor 245) may determinecoefficients for each respective determined time of arrival. At asubsequent time, the one or more transceivers may receive datatransmission 315-a received at antenna elements 305. The beam weightprocessor may then combine the received data signals from each antennaelement 305 with a respective determined coefficient associated witheach antenna element 305 to decode data signal 315-a. For example, thebeam weight processor may use maximum ratio combining (MRC) to combinethe signals according to the determined coefficients. In some cases, thebeam weight processor may generate signals for transmission from one ormore antenna elements 305 based on the determined coefficients.

In one example, the transceiver may receive training signals associatedwith each data signal. For example, the transceiver may receive trainingsignal 310-b received at each antenna element 305 from the same or adifferent transmitter and determine a time of arrival for each of theplurality of antenna elements 305 based on the received training signal310-b. The beam weight processor may then update the previouslydetermined coefficients (associated with training signal 310-a) withnewly determined coefficients from the time of arrival data associatedwith training signal 310-b for reception of data signal 315-b. Eachadditional data signal (e.g., data signal 315-n) may be preceded by atraining signal (e.g., training signal 310-n).

In another example, the training processor may determine time of arrivalinformation based on multiple training signals (e.g., training signals310-a and 310-b) received from known locations and determine spatialinformation for each antenna element 305. Using the spatial information,the beam weight processor may determine time of arrivals (e.g.,eigenmodes) for each antenna element for a data transmission 315 from aknown location (which may be the same as one of the known locations forthe training signals, or a different location). The beam weightprocessor may then combine the received data transmission from eachantenna element 305 with a respective determined coefficient associatedwith each antenna element 305 to decode the data transmission 315.

As described above, antenna elements 305 may be associated withbranches, where each branch may have multiple antenna elements 305 andmay include circuitry for pre-processing signals. In some examples,determining the coefficients for each training signal 310 associatedwith a data signal 315 may be performed on a branch basis. For example,the antenna elements 305 on each branch may be characterized orcalibrated based on training signals from one or more sources (e.g.,from at least two physically separated transmitters), and the circuitry(e.g., analog weighting circuitry) of the branch may combine signalsreceived by the elements 305 of the branch into a combined branchsignal. The transceiver may then receive training signals associatedwith each data signal, and determine time of arrivals for each combinedbranch signal from each branch based on the training signals. The beamweight processor may then determine coefficients based on the determinedtime of arrivals associated with the training signal for reception of adata signal. In some cases, the time of arrivals associated with thebranches may be used to refine the weights applied within each branch.For example, the relative locations for each leaf may be characterizedand a direction for the training signal determined from the time ofarrivals for refining the weighting used for the leaves of the branch(e.g., for the associated data signal). Coefficients may be applied toeach branch for transmission of signals based on the determined time ofarrivals, and the circuitry of each branch (e.g., analog weightingcircuitry) may apply weightings to each leaf for the transmittedsignals.

FIG. 3B illustrates an example of a signal receiving technique 350 forwireless communications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.In some examples, antenna system 101-b may implement aspects of antennasystem 101 as described in FIG. 1 and of antenna system 101-a asdescribed in FIG. 2.

Uncorrelated energy 360 may illustrate vectors associated withuncorrelated signals received via each antenna element 305 of antennasystem 101-b. The beam weight processor may combine the uncorrelatedsignals of uncorrelated energy 360 according to the determinedcoefficients from one or more training signals 310 to result incorrelated energy 355. A total amplitude and total power calculation ofcorrelated energy 355 may be calculated as follows:

${{RMS\_ Total}{\_ Correlated}{\_ Amplitude}} = {{\sum\limits_{i = 1}^{n \times k}{{RMS\_ Correlated}{\_ Amplitude}_{i}}} = {n \times k \times {RMS\_ Correlated}{\_ Amplitude}}}$RMS_Total_Correlated_SignalPower = (n × k × RMS_Correlated_Amplitude)²

Where n is a total number of branches and k is a total number of leavesof antenna system 101-b. A total amplitude and total power calculationof uncorrelated energy 360 may be calculated as follows:

${{RMS\_ Total}{\_ Uncorrelated}{\_ Amplitude}} = {\sqrt{\sum\limits_{i = 1}^{n \times k}{{RMS\_ Uncorrelated}{\_ Amplitude}_{i}^{2}}} = {\sqrt{n \times k} \times {RMS\_ Uncorrelated}{\_ Amplitude}}}$RMS_Total_Uncorrelated_Power = (n × k × RMS_Uncorrelated_Amplitude)²

Where n is a total number of branches and k is a total number of leavesof antenna system 101-b. A signal-to-noise ratio may be calculated asfollows:

Signal_(Correlated)÷Noise_(Uncorrelated)=(n×k)×(RMS_Correlated_Amplitude)²÷(RMS_Uncorrelated_Amplitude)²

Here, uncorrelated noise power grows linearly while correlated signalpower grows by a square.

FIG. 4 illustrates an example of an antenna system 400 for wirelesscommunications that supports an ultra-low cost high performancesatellite aperture in accordance with aspects of the present disclosure.Antenna system 400 may include antenna system 101-c, dish 405, andemitter 410. In some examples, antenna system 101-c may implementaspects of antenna system 101 as described in FIG. 1, antenna system101-a as described in FIG. 2, and antenna system 101-b as described inFIG. 3B. Antenna system 400 may be referred to as a hybrid dish/MIMOantenna system.

Dish 405 may represent a dish that is not perfectly parabolic. A benefitto a dish 405 that is not perfectly parabolic is that it may have loosermanufacturing requirements compared to a conventional parabolic dishwhich may lead to lower manufacturing and implementation costs. Inaddition, dish 405 may be larger than a parabolic dish manufactured totolerances typically used in satellite communication. For example,typical large parabolic dishes for satellite communication may beapproximately five (5) to fifteen (15) meters in diameter. In some casesdish 405 may be significantly larger than typical large parabolic dishesfor satellite communication, such as having a diameter of 30 meters, 50meters, 100 meters, or larger. Dish may be collapsed for launch of asatellite 105, and may be extended to a deployed shape in a variety ofways. For example, dish 405 may be formed by a conductive coating on aballoon that is expanded when the antenna system 400 is deployed inorbit. Alternatively, deployment of dish 405 may be similar todeployment of a solar sail. Yet alternatively, dish 405 may be made upof multiple rigid elements, and may be unfolded in deployment.

Radio waves 415 may be received from a transmitter by dish 405 in an RFwave-front and reflected off of dish 405 to form a dispersed focalregion. Antenna system 101-c and its associated antenna elements may beat least partially within the formed dispersed focal region of dish 405.In some examples, dish 405 may increase the RF flux power density intoantenna system 101-c, and the antenna array of antenna system 101-c maybe implemented such that a significant portion of the RF flux iscaptured by the antenna system 101-c. An efficiency of dish 405 may becalculated by taking the flux power redirected into the antenna system101-c and dividing it by the flux power collected by the antenna system101-c.

As described above, training signals from a transmitter may be used togenerate coefficients for reception or transmission of signals from theantenna elements of antenna system 400. However, determination of thecoefficients may include measurements of dish imperfections and antennaelement locations. For example, a signal received at a given antennaelement of antenna system 101-c may be reflected from multiple locationson dish non-coherently, and the dish imperfections may be measured andcombined with time of arrival information for the antenna elements todetermine the coefficients for receiving the signal coherently.

Additionally or alternatively, one or more auxiliary satellites 410 maybe used to synthesize locations of antenna elements of antenna system101-c. For example, one or more auxiliary satellites 410 may bepositioned in a known location relative to antenna system 400, and maytransmit signals that may be measured at antenna system 400 (e.g.,determining antenna vectors for each element of antenna system 101-c).Using a known location of a transmitter, the dish imperfections may bemeasured to synthesize time of arrivals or antenna element coefficientsin combination with training signals from the transmitter of a datasignal, or without receiving training signals from the transmitter ofthe data signal.

FIG. 5 shows a block diagram 500 of an apparatus 505 for an ultra-lowcost high performance satellite aperture in accordance with aspects ofthe present disclosure. In some examples, apparatus 505 may be anexample of aspects of an antenna system 101 of FIGS. 1, 2, 3B, and 4.The apparatus 505 may include a receiver 510, a training processor 515,a beam weight processor 520, and a transmitter 525. The components maycommunicate via one or more buses.

The apparatus 505 and/or at least some of its various sub-components maybe implemented in hardware, software executed by a processor, firmware,or any combination thereof. If implemented in software executed by aprocessor, the functions of the apparatus 505 and/or at least some ofits various sub-components may be executed by a general-purposeprocessor, a digital signal processor (DSP), an application-specificintegrated circuit (ASIC), a field-programmable gate array (FPGA) orother programmable logic device, discrete gate or transistor logic,discrete hardware components, or any combination thereof designed toperform the functions described in the present disclosure. The apparatus505 and/or at least some of its various sub-components may be physicallylocated at various positions, including being distributed such thatportions of functions are implemented at different physical locations byone or more physical devices. In some examples, the apparatus 505 and/orat least some of its various sub-components may be a separate anddistinct component in accordance with various aspects of the presentdisclosure. In other examples, the apparatus 505 and/or at least some ofits various sub-components may be combined with one or more otherhardware components, including but not limited to an I/O component, atransceiver, a network server, another computing device, one or moreother components described in the present disclosure, or a combinationthereof in accordance with various aspects of the present disclosure.

The receiver 510 may receive information such as packets or user data.Information may be passed on to other components of the device 505. Thereceiver 510 may include multiple receiver chains, where each receiverchain may include circuitry for processing a received RF signal (e.g.,amplifiers, mixers, analog-to-digital converters, demodulators). Eachreceive chain of receiver 510 may include circuitry to combine energycoherently from multiple antennas (e.g., MRC circuitry).

The training processor 515 may receive signals from the antenna receiverassociated with one or more training signals from a transmitter. It mayalso associate each of a plurality of antenna elements with a respectivetime of arrival based at least in part on one or more training signals.It may also determine a respective time of arrivals based at least inpart on a location of a transmitter and respective time of arrivalvectors. The one or more training signals may include an indicator oflocation information associated with the transmitter, an indicator of auser beam for the transmitter, a priority for communications from thetransmitter, or a combination thereof. The training processor 515 may beconfigured to decrypt the one or more first signals to obtain the one ormore training signals and validate the one or more training signalsbased on the decrypting.

The beam weight processor 520 may combine one or more signals associatedwith a data signal from a transmitter received via a receiver accordingto a plurality of coefficients determined based at least in part onassociations between a plurality of antenna elements and respective timeof arrivals. It may also update the plurality of coefficients based atleast in part on a second respective time of arrivals. It may alsogenerate one or more signals for transmission from a plurality ofantenna elements to a target receiver based at least in part on aplurality of coefficients determined based at least in part on theassociations between a plurality of antenna elements and respective timeof arrivals.

The training processor 515 and the beam weight processor 520 may beexamples of a processor that may include an intelligent hardware device,(e.g., a general-purpose processor, a DSP, a central processing unit(CPU), a microcontroller, an ASIC, an FPGA, a programmable logic device,a discrete gate or transistor logic component, a discrete hardwarecomponent, or any combination thereof). In some cases, the processor maybe configured to operate a memory array using a memory controller. Inother cases, a memory controller may be integrated into the processor.The processor may be configured to execute computer-readableinstructions stored in memory to perform various functions.

The transmitter 525 may transmit signals generated by other componentsof the device 505. The transmitter 525 may include multiple transmitterchains, where each transmitter chain may include circuitry forprocessing a digital signal to generate an RF signal for transmission(e.g., modulators, digital-to-analog converters, mixers, amplifiers). Insome examples, the transmitter 525 may be collocated with a receiver 510in a transceiver (e.g., which may include multiple receive/transmitchains).

FIG. 6 shows a flowchart illustrating a method 600 that supports anultra-low cost high performance satellite aperture in accordance withaspects of the present disclosure. The operations of method 600 may beimplemented by an antenna system or its components as described herein.For example, the operations of method 600 may be performed by an antennasystem as described with reference to FIGS. 1 through 5. In someexamples, an antenna system may execute a set of instructions to controlthe functional elements of the communication session delivery system toperform the functions described herein. Additionally or alternatively, acommunication session delivery system may perform aspects of thefunctions described herein using special-purpose hardware.

At 605, the antenna system may receive one or more training signals froma first transmitter via an antenna receiver. The one or more trainingsignals may include an indicator of location information associated withthe first transmitter, an indicator of a user beam for the firsttransmitter, a priority for communications from the first transmitter,or a combination thereof. In some examples, the one or more trainingsignals may be encrypted (e.g., according to a public key associatedwith a user terminal, a user beam, a group of users, a terminal type, auser type, or a combination thereof). Receiving the training signals mayinclude decrypting the training signals (e.g., according to a privatekey corresponding to the public key). The operations of 605 may beperformed according to the methods described herein. In some examples,aspects of the operations of 605 may be performed by a trainingprocessor as described with reference to FIG. 5.

At 610, the antenna system may associate a time of arrival based on thereceived one or more training signals with a respective antenna element.The operations of 610 may be performed according to the methodsdescribed herein. In some examples, aspects of the operations of 610 maybe performed by a training processor as described with reference to FIG.5.

At 615, the antenna system may receive one or more data signals from asecond transmitter via an antenna receiver. In some examples, the secondtransmitter may be the same as the first transmitter. In other examples,the second transmitter may be different from the first transmitter. Theoperations of 615 may be performed according to the methods describedherein. In some examples, aspects of the operations of 615 may beperformed by a beam weight processor as described with reference to FIG.5.

At 620, the antenna system may combine the one or more data signals inaccordance with coefficients that were determined with the plurality ofantenna elements of the antenna system and their respective time ofarrivals. The operations of 620 may be performed according to themethods described herein. In some examples, aspects of the operations of620 may be performed by a beam weight processor as described withreference to FIG. 5.

It should be noted that the methods described herein describe possibleimplementations, and that the operations and the steps may be rearrangedor otherwise modified and that other implementations are possible.Further, aspects from two or more of the methods may be combined.

Information and signals described herein may be represented using any ofa variety of different technologies and techniques. For example, data,instructions, commands, information, signals, bits, symbols, and chipsthat may be referenced throughout the description may be represented byvoltages, currents, electromagnetic waves, magnetic fields or particles,optical fields or particles, or any combination thereof.

The various illustrative blocks and modules described in connection withthe disclosure herein may be implemented or performed with ageneral-purpose processor, a DSP, an ASIC, an FPGA, or otherprogrammable logic device, discrete gate or transistor logic, discretehardware components, or any combination thereof designed to perform thefunctions described herein. A general-purpose processor may be amicroprocessor, but in the alternative, the processor may be anyconventional processor, controller, microcontroller, or state machine. Aprocessor may also be implemented as a combination of computing devices(e.g., a combination of a DSP and a microprocessor, multiplemicroprocessors, one or more microprocessors in conjunction with a DSPcore, or any other such configuration).

The functions described herein may be implemented in hardware, softwareexecuted by a processor, firmware, or any combination thereof. Ifimplemented in software executed by a processor, the functions may bestored on or transmitted over as one or more instructions or code on acomputer-readable medium. Other examples and implementations are withinthe scope of the disclosure and appended claims. For example, due to thenature of software, functions described herein can be implemented usingsoftware executed by a processor, hardware, firmware, hardwiring, orcombinations of any of these. Features implementing functions may alsobe physically located at various positions, including being distributedsuch that portions of functions are implemented at different physicallocations.

As used herein, including in the claims, “or” as used in a list of items(e.g., a list of items prefaced by a phrase such as “at least one of” or“one or more of”) indicates an inclusive list such that, for example, alist of at least one of A, B, or C means A or B or C or AB or AC or BCor ABC (i.e., A and B and C). Also, as used herein, the phrase “basedon” shall not be construed as a reference to a closed set of conditions.For example, an exemplary step that is described as “based on conditionA” may be based on both a condition A and a condition B withoutdeparting from the scope of the present disclosure. In other words, asused herein, the phrase “based on” shall be construed in the same manneras the phrase “based at least in part on.”

In the appended figures, similar components or features may have thesame reference label. Further, various components of the same type maybe distinguished by following the reference label by a dash and a secondlabel that distinguishes among the similar components. If just the firstreference label is used in the specification, the description isapplicable to any one of the similar components having the same firstreference label irrespective of the second reference label, or othersubsequent reference label.

The description set forth herein, in connection with the appendeddrawings, describes example configurations and does not represent allthe examples that may be implemented or that are within the scope of theclaims. The term “exemplary” used herein means “serving as an example,instance, or illustration,” and not “preferred” or “advantageous overother examples.” The detailed description includes specific details forthe purpose of providing an understanding of the described techniques.These techniques, however, may be practiced without these specificdetails. In some instances, well-known structures and devices are shownin block diagram form in order to avoid obscuring the concepts of thedescribed examples.

The description herein is provided to enable a person skilled in the artto make or use the disclosure. Various modifications to the disclosurewill be readily apparent to those skilled in the art, and the genericprinciples defined herein may be applied to other variations withoutdeparting from the scope of the disclosure. Thus, the disclosure is notlimited to the examples and designs described herein, but is to beaccorded the broadest scope consistent with the principles and novelfeatures disclosed herein.

1. An antenna system of a satellite, comprising: an antenna receiver; aplurality of antenna elements coupled to the antenna receiver via aplurality of flexible couplings, wherein deployed positions of theplurality of antenna elements are constrained by their position along arespective flexible coupling, and are otherwise unconstrained in one ormore spatial dimensions; a training processor configured to: receive oneor more first signals from the antenna receiver associated with one ormore training signals from a first transmitter, and associate each ofthe plurality of antenna elements with a first respective time ofarrival based at least in part on the one or more training signals; anda beam weight processor configured to combine one or more second signalsassociated with a data signal from a second transmitter received via theantenna receiver according to a plurality of coefficients determinedbased at least in part on the associations between the plurality ofantenna elements and the first respective time of arrivals.
 2. Theantenna system of claim 1, further comprising: a reflector configured toreflect radio waves to a dispersed focal region, wherein the pluralityof antenna elements are at least partially within the dispersed focalregion.
 3. The antenna system of claim 1, wherein the plurality ofantenna elements form a volumetric shape.
 4. The antenna system of claim3, wherein at least one dimension of the volumetric shape is more than100 times a distance of a wavelength of the one or more second signals.5. The antenna system of claim 3, wherein an orientation of thevolumetric shape of the plurality of antenna elements relative to anorbital position of the satellite is unconstrained in one or morespatial dimensions.
 6. The antenna system of claim 1, wherein theantenna receiver comprises a plurality of receive chains, and wherein aquantity of the receive chains of the antenna receiver is less than aquantity of the plurality of antenna elements.
 7. The antenna system ofclaim 1, wherein the antenna receiver comprises a plurality of receivechains, and wherein each of the plurality of antenna elements isassociated with a different one of the plurality of receive chains. 8.The antenna system of claim 1, wherein the second transmitter is thesame as the first transmitter.
 9. The antenna system of claim 1, whereinthe second transmitter different from the first transmitter.
 10. Theantenna system of claim 1, the training processor further configured to:receive one or more third signals from the antenna receiver, the one ormore third signals associated with a second training signal transmittedby a third transmitter; and associate each of the plurality of antennaelements with a second respective time of arrival based at least in parton the one or more third signals; and the beam weight processor furtherconfigured to update the plurality of coefficients based at least inpart on the second respective time of arrivals.
 11. The antenna systemof claim 1, the beam weight processor configured to: generate one ormore third signals for transmission from the plurality of antennaelements to a target receiver based at least in part on a secondplurality of coefficients determined based at least in part on theassociations between the plurality of antenna elements and the firstrespective time of arrivals.
 12. The antenna system of claim 1, thetraining processor further configured to: receive one or more thirdsignals from the antenna receiver, the one or more third signalsassociated with a second training signal transmitted by a thirdtransmitter; associate each of the plurality of antenna elements with asecond respective time of arrival based at least in part on the secondtraining signal; and determine spatial information for each of theplurality of antenna elements based at least in part on the firstrespective time of arrivals and the second respective time of arrivals.13. The antenna system of claim 12, the training processor furtherconfigured to: determine the plurality of coefficients based at least inpart on the spatial information and a location of the secondtransmitter.
 14. The antenna system of claim 1, wherein the one or moretraining signals comprise an indicator of location informationassociated with the first transmitter, an indicator of a user beam forthe first transmitter, a priority for communications from the firsttransmitter, or a combination thereof.
 15. The antenna system of claim1, wherein the training processor is configured to: decrypt the one ormore first signals to obtain the one or more training signals; andvalidate the one or more training signals based on the decrypting.
 16. Amethod for receiving radio waves at an antenna system of a satellite,comprising: receiving one or more first signals using a plurality ofantenna elements, the one or more first signals corresponding to atraining signal transmitted by a first transmitter, wherein theplurality of antenna elements are each coupled with one of a pluralityof flexible couplings, and wherein deployed positions of the pluralityof antenna elements are constrained by their position along a respectiveflexible coupling, and are otherwise unconstrained in one or morespatial dimensions; associating each of the plurality of antennaelements with a first respective time of arrival based at least in parton the one or more first signals; receiving one or more second signalsusing the plurality of antenna elements, the one or more second signalscorresponding to a data signal transmitted by a second transmitter; andcombining the one or more second signals according to a plurality ofcoefficients determined based at least in part on the associationsbetween the plurality of antenna elements and the first respective timeof arrivals.
 17. The method of claim 16, wherein the plurality ofantenna elements form a volumetric shape.
 18. The method of claim 17,wherein at least one dimension of the volumetric shape is more than 100times a distance of a wavelength of the one or more second signals. 19.The method of claim 17, wherein an orientation of the volumetric shapeof the plurality of antenna elements relative to an orbital position ofthe satellite is unconstrained in one or more spatial dimensions. 20.The method of claim 16, wherein receiving the one or more first andsecond signals comprises receiving the one or more first and secondsignals via a plurality of receive chains.
 21. The method of claim 20,wherein a quantity of the plurality of receive chains is less than aquantity of the plurality of antenna elements.
 22. The method of claim20, wherein each of the plurality of antenna elements is associated witha different one of the plurality of receive chains.
 23. The method ofclaim 16, wherein the second transmitter is the same as the firsttransmitter.
 24. The method of claim 16, wherein the second transmitteris different from the first transmitter.
 25. The method of claim 16,further comprising: receiving one or more third signals using theplurality of antenna elements, the one or more third signals associatedwith one or more second training signals from a third transmitter;associating each of the plurality of antenna elements with a secondrespective time of arrival based at least in part on the one or morethird signals; and updating the plurality of coefficients based at leastin part on the second respective time of arrivals.
 26. The method ofclaim 16, further comprising: generating one or more third signals fortransmission from the plurality of antenna elements to a target receiverbased at least in part on a second plurality of coefficients determinedbased at least in part on the associations between the plurality ofantenna elements and the first respective time of arrivals; andtransmitting the one or more third signals from the plurality of antennaelements.
 27. The method of claim 16, further comprising: receiving oneor more third signals from the antenna receiver, the one or more thirdsignals associated with a second training signal transmitted by a thirdtransmitter; associating each of the plurality of antenna elements witha second respective time of arrival based at least in part on the secondtraining signal; and determining spatial information for each of theplurality of antenna elements based at least in part on the firstrespective time of arrivals and the second respective time of arrivals.28. The method of claim 27, the method further comprising: determiningthe plurality of coefficients based at least in part on the spatialinformation and a location of the second transmitter.
 29. The method ofclaim 16, wherein the one or more training signals comprise an indicatorof location information associated with the first transmitter, anindicator of a user beam for the first transmitter, a priority forcommunications from the first transmitter, or a combination thereof. 30.The method of claim 16, further comprising: decrypting the one or morefirst signals to obtain the one or more training signals; and validatingthe one or more training signals based on the decrypting.